Don't mention (@) people in integrated chatrooms?

I’ve set up chat integration to a Matrix room, which is also bridged to a Telegram chat group.

Currently the chat_integration.provider.matrix.formatted_message text includes %{user}, which expaneds to either @username or @username (fullname). This works fine in the Matrix room but will mention someone on the Telegram side, who may not be the same person as in the forum.

So I’d like to have a way to get rid of the @ symbol. Even better, make it configurable to use only fullname and fallback to username when fullname is empty.